Alarm system for electric refrigerators



Aug. 24, 1948. J. BAUMAN ALARM SYS'IBI FOR ELECTRIC REFRIGBRATOBS 2 Sheets-Sheet 1 Filed Oct. 28, 1944 Aug. 24, 1948. J. J. BAUMAN ALARM SYSTEI FOR ELECTRIC REFRIGBRATCRS 2 Sheets-Shoat 2 Filed Oct. 28, 1944 jyzbu firs Patented Aug. 24, 1948 ALARM SYSTEM FOR ELECTRIC BEFRIGERATORS John J. Bauman, Abington, Pa., assignor, by mesne assignments, to Philco Corporation, Philadelphia, Pa., a corporation of Pennsylvania Application Ootober as, 1944, Serial No. 580,845

This invention relates to. refrigeratorsand more particularly to novel means for indicating an abnormal or undesired condition of the refrigerating apparatus. The invention is especially applicable to that type of refrigerator having a freezer chest compartment for the storage of frozen food. r In the case of an ordinary household refrigerator which is used to store foodstuffs for daily use, any failure or abnormal condition would be readily noticed and therefore the provision of an alarm or indicator is not usually warranted. However, in the case of a refrigerator having provision for storing foodstuffs for use at some future time, the provision of such an indicator is highly desirable. An example of such a refrigerator is one having a freezer chest compartment in which a large quantity of foodstuffs may be stored. In such case, anabnormal condition is likely to go unnoticed and a resulting spoilage of foodstuffs may be very substantial. The desirability of a suitable alarm or indicator in such an apparatus is quite apparent.

In my copending applications Serial Numbers 551,977 and 551,978, both filed August 30, 1944, there are disclosed and claimed novel devices for indicating an abnormal condition in a refrigerating apparatus, which devices embody means for rendering the indicator inoperative at certain times and for automatically restoring the operative condition of the indicator. In certain embodiments of the last mentioned copending application, the operativeness of the alarm or indicator device is controlled according to the refrigerating cycle. The present application is directed to an improved and commercially desirable apparatus of the same general character in which the operativeness of the alarm or indicator device is controlled according to the commencement of a refrigerating cycle, as will be described more fully hereinafter.

The principal object of the present invention, therefore, is to provide a novel apparatus for the purpose above indicated.

Another object of the invention is to provide an apparatus in which the operativeness of the alarm or indicator device is controlled according to the commencement of a refrigerating cycle after a desired temperature value has been reached.

A further object of the invention is to .provide an apparatus of this character in which the means for controlling the operativeness of the alarm or indicator device includes a switch which is controlled according to the temperature ad- 11 Claims. (Cl. 02-2) ill iustment and also according to a refrigerating cycle.

Other objects and features of the invention will be apparent from the followingdetailed description. In the accompanying drawings:

Fig. 1 illustrates a refrigerating apparatus or system embodying the present invention;

Fig. 2 is a fragmentary plan view, showing the various settings or positions of the manual control knob;

Fig. 3 is a perspective view of an electro-magnetically operated switch device, which is employed in the apparatus;

Fig. 4 is a fragmentary view, partly in elevation and partly in section, of a modification;

lilg. 5 is a view taken along line 5-5 of Fig. 4; an

Fig. 8 is a perspective view of the electromagnetic switch employed in the modified apparatus.

Referring first to Fig. 1, there is shown on a greatly reduced scale, an electric refrigerator Ill, including a freezer chest compartment ll, having an associated cooling unit or evaporator II. The refrigerator includes the usual motorcompressor unit l3, condenser ll, feed line It,

restrictor I! and suction line FL The motor of unit II is of a type having a starting winding II and a running winding It. For example, the motor may be a single phase induction motor employing a starting winding to provide the necessary starting torque. Mention is made of the Y specific character of the motor because the circult of the starting winding is employed, according to the present invention, in the control of theoperativeness of the alarm or indicatin device, as described hereinafter. Aside from this,

the present invention is not concerned with the details of the refrigerator structure or the refrigerating system which may be of conventional form The refrigerating system is controlled by means of an adjustable thermostatic control device 20. The parts of this device are shown as being conveniently mounted on a support or casing 2| which may be suitably disposed as a part of the entire refrigerating apparatus, The thermostatic control is preferably effected by means of a feeler bulb 22 arranged to detect temperature variations within the compartment ii. As illustrated, the feeler bulb may be positioned in engagement with a portion of the refrigerant conduit, whose temperature determines the temperature within compartment H. The feeler bulb 22 operates a bellows 23 through the medium of an expansible fluid within the conduit 24, as will be well understood. The bellows 23 actuates a bell-crank lever 25, which is pivoted at 26, against the action of a spring 21, whose pressure is adjustable by the manual rotation of a control knob 23. The lower end of spring 21 engages lever 25, whilethe upper end of the spring abuts against a member 21a threadedly engaging a shaft 29, upon which the control knob 28 is mounted. The shaft 23 is rotatably supported by easing 2| and by a bracket 30 fixedly mounted on the casing. A flange'or collar 3| on shaft 29 engages a flange 32 on bracket 30 to prevent upward longitudinal movement of the shaft, the flange 32 also serving as a journal for the shaft. Thus, it will be seen that rotation of shaft 23 by means of knob 23 varies the axial position of member 21a, thereby varying the pressure of spring 21.

A switch 33 is operated by the lever 25 and serves to control the motor circuit to which reference will be made later. Switch 33 comprises a stationary contact 34, suitably insulated from casing 2|, and a movable contact 35 carried by an arm 36, which is pivoted on a knife-edge pivot 31 on the stationary bracket 30. A spring 38 has one end connected to arm 36 at 39, while the other end of the spring is connected to lever 25 at 40.

Normally the parts are positioned as shown, with the axis of spring 38 to the left of the pivot point, and the switch 33 is open. However, when lever 25 moves clockwise about its pivot 26, the axis of spring 38 is moved to the right of the pivot 31 and causes arm 36 to move so as to bring the contact 35 into engagement with contact '34. Thus, whenever the temperature within compartment rises sufiiciently to cause operation of the above described parts, switch 33 is closed to initiate operation of the refrigerating system so as to lower the said temperature. It will be apparent that the adjustment of the pressure of spring 21 by means of knob 28 determines the temperature which will be maintained within compartment As shown in Fig. 2, the control knob 28 has four principal positions which are preferably designatedrespectively off, normal, "cold and continuous." The normal setting is used for ordinary refrigerator operation in the manner of the usual domestic refrigerator. This position might, for example, correspond to a temperature condition in the neighborhood of 38 to 40 F. The cold setting is used to maintain stored foodstufis at a lower temperature, such as to maintain the stored foodstuffs in a frozen condition (for example, from 0 to 5 F.). The continuous setting is used to quick-freeze foodstuffs by rapidly decreasing the temperature within compartment ii to a substantially lower temperature than that which obtains during the cold setting. As an example, this lowertemperature might be in the neighborhood of 25 below zero. It should be pointed out that the word continuous is not .intended to mean that the refrigerating system operates continuously when the control knob is at this setting. 01 course, at this setting the cycle of operation of the refrigerating system will be longer than it will be at the higher temperatures.

As thus far described, the device 20 constitutes an adjustable thermostatic means for controlling the operation of the refrigerating system. In addition, provision is made for indicating abnormal conditions of the refrigerating apparatus by means of the additional structure now to be described. At the upper end of lever 25, there is provided a double contact member 4|, which is suitably insulated from the lever. Arranged c0- indicator device 45 preferably comprises a conventional buzzer and is so illustrated, it may take the form of any other conventional audible or visual signaling device.

In accordance with the present invention, provision is made for rendering the alarm or indicator device inoperative at certain times and for automatically restoring the operative condition of said device at other times. ativeness of the indicator device is controlled by the adjustment of knob 23 and by the starting circuit of the refrigerator motor. To accomplish these ends, there is provided a normally open switch comprising resilient contact arms 43 and 41 carried by a supporting bracket 43 and suitably insulated therefrom. Under the influence of their own resilience, these contact arms assume the relative positions shown in Fig. 1 so that the switch is open. This switch is included in the alarm circuit which also includes conductor 49, switch 4i-42-43, conductor 50, conductor 5|, the alarm device 45, and conductor 52, Since the alarm device will usually be operated at low voltage, a step-down transformer 53 may be employed to derive the required energy from the supply conductors 54 and 55.

Associated with the switch 4341 is an electromagnet 56 mounted on bracket 43 and having an associated armature 51, the upper end which is pivotally attached to bracket 43 at 53. A tongue on the lower portion 01' armature 51 (see Fig. 3) passes through an aperture in a lateral extension 59 of contact arm 41, so that attraction of said armature by the electromagnet causes closure of the switch 46-41. A latch or detent member 60 is cooperatively associated with the tongue on armature 51 and is carried by a resil-' ient arm 6| secured to the mounting bracket 43. A vertical slide bar 62, extending through a slot} in bracket 43, has its lower end interconnected with the free end of arm 6|. At its upper end, the slide bar 62 carries a knob 63. A bell crank lever 64 is pivotally mounted on casing 2| at 33', and has an extending tongue 66 which projects through an aperture 61 (Fig. 3) in the slide bar 62. The other arm 63 of the bell-crank lever 64 engages a cam 63 carried by shaft 23. As

shown in Fig. 2, the cam 63 has raised portions 10 and 1| and depressions 12 and 13. The purpose of the structure just described is to control the positioning of the latch member 63, as will be seen more clearly later.

Referring to the motor circuits, the circuit of the running winding |3 extends from supply conductor 54 through conductor 14, winding l3, conductor 15, the winding of a starting relay 16, conductor 11, and thermal overload relay 13-, conductor 10, switch 33, and conductor 36, to the other supply line 55. The circuit for the starting winding |3 extends from supply conductor 34 through conductor 14, winding i3, conductor 3|,

Moreover, the opermay be assumed that the apparatus is being put into operation for the first time, the control knob 2| being in the "01! position, and the other parts being in the positions shown. Since arm I of bell crank lever 44 is engaged by the raised portion ll of cam 49, the slide bar 62 is lowered and the latch member .60 is maintained in an ineflective position against the resilience of arm I, as shown. As the control knob "is rotated in a counterclockwise direction from the "off" position, the pressure of spring 21 is decreased, causing clockwise rotation of bell crank lever 25 and consequent closure of switch 22. The running circuit of motor I: is thus completed and relay I4 is energized, causing completion of the motor starting circuit, which, however, remains closed (or a very short interval, e. g. about of a second. The momentary closure of the startin circuit energizes electromagnet 5 which closes switch 44-41, but the latter reopens almost immediately due to the fact that the latch member II is ineffective. If contacts 4l43 closes while switch 46-41 is closed, the alarm device 45 will be energized instantaneously but this will only serve to indicate that the temperature-lowering cycle has commenced.

If the knob 24 is adjusted to the "normal setting, the switch 4641 will remain open because the bell crank lever 64 will be maintained in the position shown. Under such operating condition, the temperature within compartment II will be lowered to the value corresponding to the normal" setting, and the lever 25 will gradually return to the position shown. During operation at the "normal" setting, the alarm device is maintained inoperative by switch 46-41, due to the design of cam N. If desired, however, the cam may be designed so as to render the alarm device operative in the norma setting, as in the case of the other settings now to be described.

In considering operation of the apparatus at other settings or adjustments corresponding to lower temperatures, it should be remembered that the period of energization of the starting circuit of motor I: is very short. When the switch 33 closes, the running winding I9 is energized through a circuit which includes the winding of relay It and since a relatively large initial current is drawn by the motor, relay '6 is energized, thereby completing the starting circuit including the starting winding l8. After a very short period, as mentioned above, the motor comes up to speed and the current flowing through the winding of relay 16 decreases sufficiently to cause the relay to drop out, thereby interrupting the starting circuit, which includes the winding of electromagnet 5. This operation is characteristic of motors of the type employed, and the present invention makes use of the short period of energization of the starting circuit to energize the electromagnet 56.

Continuing with the operation of the apparatus, it may be assumed that operation has been taking place at the "norma setting and that it is desired to eil'ect operation at the cold setting. Accordingly, the operator moves the control knob 24 counterclockwise from the normal setting to the cold" setting. This decreases the force exerted by spring 21 and causes closure of switch 82 (and also contacts 4! and 42), thereby starting the motor The short starting period is completed while the raised portion 10 of cam i9 is still effective and therefore the latch member ill remains in its inefiective position until the control knob reaches the "cold" setting. at

which time the arm CI of lever 4 enters recess I2 of cam 42, permitting the latch member 64 to rise to its elective position due to the resilience of arm ll. However, the switch 46-41 is open at this time, since the electromagnet 54 will have been deenergized by the dropping out of relay I! at the end of the very short motor starting period. Therefore, although the alarm device may be actuated momentarily, as mentioned previously, it will be inoperative during the pulldown" cycle from normal to "cold." temperature within compartment H reaches the cold value, the lever 25 will have assumed the position shown, and of course the switches 33 and 4l42 will be opened due to the counterclockwise movement of lever 25. When the temperature within compartment ii rises sufllciently to cause reclosure of switch 32, the motor ll will start and the electromagnet 58 will be energized,

' attracting its armature 51, which is then held by latch member 4. Accordingly, the switch 46-41 is closed during the commencement of the second refrigerating cycle following the adjustment of knob 2|, and the switch is maintained closed by latch member I.

During operation of the apparatus at the cold" setting, any abnormal increase or decrease of the temperature within compartment II will cause contact 4| to engage one of the contacts 42-43, thereby energizing the alarm or indicator device 45 so as to indicate that the temperature has deviated a substantial amount from the cold" value. Thus, the alarm device is operative during the "cold" setting to indicate an abnormal condition. If the alarm device should operate, its circuit may be interrupted by pressing knob 63 downward so as to move the latch member 64 to its ineflectlve position and thus permit switch 44-41 to open. When the cause of the abnormal condition is determined and corrected, operation may be resumed and the switch 4H1 will be closed at the start of the first refrigerating cycle thereafter, since the latch member 60 is permitted to rise when knob 63 is released.

Assuming that the apparatus has been operating at the "cold" setting and that it is desired to operate it at the "continuous" setting. as where it is desired to quick-freeze foodstufls stored in compartment II, the operator rotates the knob 28 counterclockwise toward the continuous setting. The raised portion H of cam 69 immediately efiects movement. of latch member 60 to its ineffective position and maintains it in that position during the very short motor-starting period. When the arm 88 of lever 64 encounters recess I3, i. e. when the knob 28 reaches its continuous setting, the latch member 60 is permitted to rise to its efiective position, but since the electromagnet 56 is then deenergized, the switch 46-41 remains open. Thus, during the pull-down" cycle from "cold to continuous. the alarm device 45 is rendered inoperative even though the switch 4841 will be closed momentarily at the beginning of such pull-down cycle. At the start of the succeeding refrigerating cycle, the electromagnet 5i will be energized momentarily and the switch 46-41 will be maintained closed by the latch member 60. Thus, the alarm device 45 is rendered operative to indicate any abnormal variation of the temperature within compartment ll while operating at the continuous setting.

Assume now that it is desired to raise the temperature within compartment II from the "con- When the tinuous value to the "cold value. The operator rotates the knob 28 clockwise from the continuous setting, thereby increasing the force of spring 21 and causing counterclockwise movement of lever 25 and closure of contacts 4| and 42. At the same time, the projection or raised portion H of cam 68 trips the latch member 80, thus opening switch 464'l. The latch member returns to its effective position when the arm 68 recedes into recess 12, but the switch 464'| remains open. Thus, during the rise of the temperature within compartment II from the continuous value to the "cold" value, the alarm or indicator device is rendered inoperative even though contacts 4| and 42 will be closed during the beginning of the temperature-raising period.

When the temperature within compartment reaches the cold" value, lever 25 will have resumed the position shown. A further increase in temperature will cause closure of switch 33 to start motor l3. During the short starting period, the electromagnet 56 is momentarily energized and the switch 46-41 is latched in closed position. Thus, the alarm device is rendered operatlve and remains so during operation of the apparatus at the cold setting.

Assume now that the knob 28 is again rotated clockwise to raise the temperature within compartment H from the "cold value to the normal" value. The raised portion of cam 69 trips the latch member 60 and maintains the latter in its ineffective position so that the alarm device is rendered inoperative during operation of the apparatus at the normal setting.

Regardless of the adjusted position of knob 28 and the corresponding temperature which being maintained within compartment H, the insertion of a considerable quantity of warm food in compartment Il may cause the temperature to rise sufiiciently to cause contact 4| to engage contact 43. If the knob is set at either the "cold" or continuous" setting, the alarm device will be operated and its operation may be interrupted by pressing knob 63 downward to trip the latch member 60. At the start of the succeeding refrigerating cycle, the switch 46-41 will be closed and held closed by latch 60, as above described.

During operation at either the cold setting or the "continuous" setting, a failure of the refrigerating system or a power failure will cause an abnormal rise in the temperature within compartment II and will cause contact 4| to engage contact 43, thus energizing the alarm device.

As stated previously, the knob 63 may be depressed to shut off the alarm and when operation is resumed, the alarm circuit will be rendered operative at the beginning of the first refrigerating cycle.

In the event that the bellows 23 should lose its charge, lever 25 will rotate counterclockwise, bringing contact 4| into engagement with contact 42. In this instance also the alarm device will be energized and the above mentioned procedure may be followed.

From the foregoing description, it will be seen that the invention-provides a novel mechanism by which the alarm device is rendered opt :ative during operation of the apparatus at certain temperatures, and the said device is rendered inoperative during temperature-changing cycles. It will be seen further that these desired results are accomplished by controlling the switch 46-41 according to the adjustment of, the control knob and also according to the refrigerating cycle.

In Figs. 4 to 6 there is disclosed a commercially preferred modification of the apparatus, in which certain parts of the above described embodiment are eliminated, and in which the alarm device is rendered operative at the normal" setting as. well as the other operative settings.

Referring to the said figures, in this instance the cam 69 (Fig. 1) and the associated bell crank lever 64 are eliminated, and the slide barto is actuated directly by the control knob 28a, the latter being depressable or movable inward in addition to its being rotatable. The bracket 48a is mounted on a second bracket 83 which in turn is secured to the casing 2 la. and serves to support a dial plate 84 having the different settings marked thereon, as shown in Fig. 5. Aflixed to the upper end of the rotatable shaft 18a is a member 85, upon which the control knob Ila is movably mounted. The upper end of member 85 is flanged and is provided with teeth 88 which are adapted to cooperate with similar teeth 81 on the inside of the knob 28a. The knob is slidably carried by the flange of member 85 so as to be depressably movable inward, as above mentioned. A spiral spring 88 is disposed in'a recess 89 within member 85, and serves to urge the control knob outwardto the position shown. The upper end of spring 88 is seated in a cup shaped retainer 88 which is engaged by a projection 9| on the inside of the control knob. The outward movement of the knob is limited by a split ring 92 which is carried by the knob, as shown, and which is adapted to engage the flange of member '85 Secured to member 85 below the control knob is a pointer 93 (see Fig.5) which serves to indicate the setting of the apparatus.

The slide bar 62a is shaped as illustrated, and it extends upwardly through an opening 94 in bracket 83 and also through an opening 95 in the dial plate 84. The upper end of the slide bar is disposed beneath the outer portion of knob Ila so as to be engageable by the latter as hereinafter described. In addition to the above-described modifications, the detent member 88 oi Fig. 1 is also eliminated, and an aperture 96 (see Fig. 6) is provided in the resilient arm 8|a and'serves to latch the armature 51a. Thus, in this instance. the arm Gla serves directly as the latching means for the armature, by reason of the aperture 98, into which'the tongue of the armature may project. Aside from the above described modifications, the apparatus is the same as that disclosed in Fig. 1.

When the pointer 93 is in the o position. the apparatus is in the condition shown in Fig. 1, and the knob 28a is in its inoperative position, as shown in Fig. 4, and is free of the slide bar 82a. Since the armature 51a is out of alignment with the aperture 96. the resilient arm 61a abutsagainst the lower end of the armature.

Suppose now that the operator wishes to effect operation at the normal setting. This is accomplished by pressing knob 28a inward to effect engagement of teeth 86 and 81, and by rotating the knob counter-clockwise so as to move the pointer 93 to the desired setting. This manual operation decreases the pressure of spring 21 (Fig, 1) and initiates operation of the refrig erating apparatus, as previously described. The inward movement of knob 2811 causes it to engage the upper end of slide bar 82a, thereby lowering the slide bar and disengaging arm 8|a from armature 61a. Thus, the arm 6la is maintained in an inefiective position during the adjustment to the duired setting. By the time the control knob is released, the very short starting period of the refrigerator motor has terminated, so that the electromagnet "a is deenergized and the switch la-"dis open. Therefore, the parts resume the positions shown in Fig. 4, and the alarm device is maintained inoperative during the pull-down" cycle from oil" to "normal." While the alarm device may be actuated momentarily during the short starting period, as previously described, this merel serves to indicate that the apparatus has commenced to function.

At the start of the second refrigerating cycle. after the pull-down" cycle has been completed, the electromagnet "a is momentarily energized. closing switch ltd-41a and causing the tongue on armature 81a to move into the latching aperture II. Thus, the alarm device is rendered operative in response to commencement of the second refrigerator cycle. In the event that an abnormal condition occurs, said device will be actuated as previously described,

When it is desired to effect operation at a difierent setting, the above described operation of the control knob 28a is repeated. Depression of the control knob unlatches the armature 51a. per- "mitting the switch la-41a to open. It is believed that further description of the operation is unecessary in view of the preceding description.

Thus, it will be seen that the modified apparatus, as illustrated in Figs. 4 to 6, effects operation in the same manner as described with reference to the embodiment of Fig. 1, except that the alarm device is rendered operative during normal setting as well as the other settings. as previously stated. The modified structure of Figs. 4 to 6 is believed to be preferable from the standpoint of commercial practice.

While the invention has been illustrated and described with reference to certain embodiments. it will be understood that various other changes and modifications may be made without departing from the scope of the invention as defined by the appended claims.

I claim:

1. In an apparatus for indicating excessively high or low temperaturflzwithin a refrigerated area, switch means operable in response to predetermined excessively high and low temperatures within said are indicating means operable by said switch means. additional switch means for rendering said indicating means temporarilyv inoperative, and means. controlled in accordance with the commencement oi a refrigerating cycle for actuating said additional switch means so as to render said indicating means operative.

2. In an apparatus for indicating excessively high or low temperature within a refrigerated area, thermal-responsive means arranged for actuation according to the temperature within said area, a member movable by said means in opposite directions in response to temperature variations about a predetermined optimum temperature, contactmeans carried by said member. other contact means arranged cooperatively with said first contact means and engageable thereby whenever the temperature within said area is excessively high or low, electrical-indicating means operable by the engagement of said contact means, switch means for rendering said indicating means temporarily inoperative. and means controlled in accordance with the commencement of a refrigerating cycle for actuating said switch means so as to render said indicating means operative.

3. In an electrical refrigerator apparatus including a storage compartment, a refrigerating system including an electric motor, a thermostatically-operable switch in circuit with said motor to control the operation of the refrigerating system. indicating means, a switch in circuit with said indicating means and operable in response to excessively high or low temperatures within said compartment, a second switch in circuit with said indicating means for rendering said indicating means temporarily inoperative, means for opening said last-named switch, and means in circuit with said motor for effecting closure of said last-named switch at the commencement of a refrigerating cycle.

4. In an electrical refrigerator apparatus including a food storage compartment, a refrigerating system including an electric motor, ad- Justable thermostatic means for controlling the operation of said motor, whereby the temperature within said compartment may be lowered to a desired value and maintained thereat, electrical indicating means, switch means in circuit with said indicating means and operable in response to substantial deviation of said temperature from said value, and means for rendering said indicating means inoperative while said temperature is being lowered to a desired value, and for rendering said indicating means operative in response to commencement of a refrigerating cycle after said temperature has reached said value.

5. In an electrical refrigerator apparatus including a food storage compartment, a refrigerating system including an electric motor, adjustable thermostatic means for controlling the operation of said motor, whereby the temperature within said compartment may be lowered to a desired value and maintained thereat, electrical indicating means, switch means in circuit with said indicating means and operable in response to substantial deviation of said temperature from said value, a normally open switch also in circuit with said indicating means for rendering the latter inoperative while said temperature is being lowered to a desired value, latching means adapted to be positioned to hold said switch closed, means for positioning said latching means to be eflective after the temperature-lowering cycle has commenced, and means for closing said switch in response to the succeeding refrigerating cycle after said temperature has reached said value.

6. In an electrical refrigerator apparatus including a food storage compartment, a refrigerating system including an electric motor, adjustable thermostatic means for controlling the operation of said motor, whereby the temperature within said compartment may be lowered to a desired value and maintained thereat, electrical indicating means, switch means in circuit with said indicating means and operable in response to l l erating cycle after said temperature has reached said value.

7. In an eiectrical refrigerator apparatus including a food storage compartment, a refrigerating system including an electric motor, adjusttive in response to commencement of a refrigerating cycle after said temperature has reached said value.

8. In an electrical refrigerator apparatus including a food storage compartment, a refrigerating system including a motor having a starting winding and an associated circuit including a relay which opens said circuit after the motor has started, adlustable'thermostatic means for controlling the operation of said motor, whereby the temperature within said compartment may be changed to a desired value and maintained thereat, electrical indicating means, switch means in circuit with said indicating means and operable in response to substantial deviation of said temperature from said value, additional switch means in circuit with said indicating means for rendering said indicating means inoperative while said temperature is being changed to a desired value after adjustment of said thermostatic means, and means responsive to energization of said starting winding circuit for actuating said additional switch means to render said indicating means operative upon commencement of a refrigerating cycle after said temperature has reached the desired value.

9. In an electrical refrigerator apparatus including a food storage compartment, a refrigerating system including a motor having a starting winding and an associated circuit including a relay which opens said circuit after the motor has started, adjustable thermostatic means for controlling the operation of said motor, whereby the temperature within said compartment may be changed to a desired value and maintained thereat, electrical indicating means, means in circuit with said indicating means and operable in-response to substantial deviation of said temperature from said value, a switch also in circuit with said indicating means for rendering said indicating means inoperative while said temperature is being changed to a desired value after adjustment of said thermostatic means, and means responsive to energization of said starting winding circuit for actuating said switch so as to render said indicating means operative upon commencement of a refrigerating cycle after said temperature has reached the desired value.

10. In an electrical refrigerator apparatus including a food storage compartment, a refrigerating system including a motor having a starting winding and an associated circuit including a relay which opens said circuit after the motor has started, adjustable thermostatic means for controlling the operation of said motor, whereby the temperature within said compartment may be changed to a desired value and maintained thereat, electrical indicating means, switch means in switch 12 circuit with said indicating means and operable in response to substantial deviation of said temperature from said value, a normally open switch also in circuit with said indicating means for rendering the latter inoperative while said temperature is being changed to a desired value after adjustment of said thermostatic means, latching means adapted to be positioned to hold said switch closed, means for positioning said latching means to be eifective after the temperaturechanging cycle has commenced, and means for closing said switch in response to the succeeding refrigerating cycle after said temperature has reached the desired value.

11. In an electrical refrigerator apparatus including a food storage compartment, a refrigerating system including a motor having a starting winding and an associated circuit including a relay which opens said circuit after the motor has started, adjustable thermostatic means for controlling the operation of said motor, whereby the temperature within said compartment may be changed to a desired value and maintained thereat, electrical indicating means, switch means in circuit with said indicating means and operable in response to substantial deviation of said temperature from said value, a normally open switch also in circuit with said indicating means for rendering the latter inoperative while said temperature is being changed to a desired value after adjustment of saidthermostatic means, latching means adapted to be positioned to hold said switch closed, means responsive to the adjustment of said thermostatic means for positioning said latching means to be effective after the temperature-changing cycle has commenced, and means for closing said switch in response to the succeeding refrigerating cycle after said temperature has reached the desired value.

12. In an electrical refrigerator apparatus including a food storage compartment, a refrigerating system including a motor, adjustable thermostatic means for controlling the operation of said motor, whereby the temperature within said compartment may be changed to a desired value and maintained thereat, electrical indicating means, switch means in circuit with said indicating means and operable in response to substantial deviation of said temperature from said value, and additional switch means in circuit with said indicating means and controlled by the adjustment of said thermostatic means and by the energization of said motor for rendering said indicating means inoperative during the temperature-changing interval and for rendering the indicating means operative after the desired temperature value has been reached.

13. In an electrical refrigerator apparatus including a food storage compartment, a refrigerating system including a motor having a starting circuit which is energized only during starting of the motor, adjustable thermostatic means for controlling the operation of said motor, whereby the temperature within said compartment may be changed to a desired value and maintained thereat, electrical indicating means, switch means in circuit with said indicating means and operable in response to substantial deviation of said temperature from said value, and additional switch means in circuit with said indicating means and controlled by the adjustment of said thermostatic means and by the energization of said motor starting circuit for rendering said indicating means inoperative during;

the temperature-changing interval and for ren- 13 dering the indicating means operative after the desired temperature value has been reached.

14. In an electrical refrigerator apparatus including a food storage compartment, a refrigerating system including a motor, adjustable thermostatic means for controlling the operation of said motor, whereby the temperature within said compartment may be changed to a desired value and maintained thereat, electrical indicating means, switch means in circuit with said indicating means and operable in response to substantial deviation of said temperature from said value, and additional switch means in circuit with said indicating means and controlled by the adjustment of said thermostatic means and by the energization of said motor for rendering said indicating means inoperative during the prevalence of a certain temperature value and for rendering the indicating means operative when the temperature is lowered to another value.

15. In an electrical refrigerator apparatus including a food storage compartment, a refrigeratlng system including a motor, adjustable thermostatic means for controlling the operation 0! said motor, whereby the temperature within said compartment may be changed to a desired value and maintained thereat, a rotatable control knob for adjusting said means, a cam operable by said control knob, electrical indicating means, switch means in circuit with said indicating means and operable in response to substantial deviation oi said temperature from said value, and additional switch means in circuit with said indicating means and controlled by said cam and by the energiaation of saidmotor for rendering said indlcating means inoperative during the temperature-changing cycle and for rendering the indicating means operative after the desired temperature value has been reached.

16. In an electrical refrigerator apparatus including a food storage compartment, a refrigerating system including a motor, adjustable thermostatic means ior controlling the operation or said motor, whereby the temperature within said compartment may be changed to a desired value and maintained thereat, a depresslble and rotatable control knob for adjusting said means,

electrical indicatin means, switch means in clrcult with said indicating means and operable in response to substantial deviation of said temperature from said value, and additional switch means in circuit with said indicating means and controlled by the depression of said knob and by the energization of said motor for rendering said indicating means inoperative during the temperature-changing cycle and for rendering the indicating means operative after the desired temperature value has been reached.

17. In an apparatus for indicating excessively high or low temperature within a refrigerated area, switch means operablein response to predetermined excessively high and low temperatures within said area, indicating means operable by said switch means, and means ior rendering said indicating means temporarily inoperative, and for rendering said indicating means operative in accordance with the commencement of a refrigerating cycle.

JOHN J. BAUMAN. 

